Sterling: New reverse osmosis water treatment plant online and ramping up to full production

…by the end of February, [city engineers] say, 80 percent of the city’s water will run through dozens of stacked reverse osmosis (RO) filters, squeezing out pollutants to meet state standards.

“It’s not something you call in and say, ‘Hey, deliver this to us,'” said Mark Youker, construction manager for Hatch Mott McDonald, which has overseen the architecture and engineering of the project. “It’s a lot more complicated than that.”

Plans to build the plant started around September 2008, when the Colorado Department of Public Health and Environment issued an enforcement order to get the city’s water standards up to compliance within a given time frame. The main contaminant, among others, was the water’s naturally-occurring uranium levels, which could increase an individual’s cancer risks over longer exposures.

Youker said before the plant was constructed, Sterling’s water was pumped directly from wells across the county, treated with chlorine at four separate stations and delivered directly to city homes, farms and businesses.

When the plant becomes fully operational, the city’s raw well water will all instead flow straight to the one spot for treatment. It’s capable of providing 9.5 million gallons of water to the city per day, though the average demand is only about 4 million gallons.

The water will run through a filtration system before it’s chlorinated, and be pumped out as a 80/20 mix of RO-treated to untreated water; Youker said the city has been receiving the “20 percent,” filtered water for about two months already.

Workers at the new Sterling Water Treatment Plant monitor every aspect of the treatment process through a monitor in their control room. (David Martinez/Journal-Advocate)
Ryan Walsh, the project engineer, said the mix holds several structural and taste benefits.

“The first goal (of treatment) is to bring the city’s water to compliance with the new state standards,” Walsh said. “The second is to bring water that more aesthetically pleasing and requires less maintenance.”